I never really had this issue because I used Google Suite with a domain. (That’s what it was called back then.)

So I can have email aliases under that domain, and even choose the alias for outgoing email.

However! This creates an extra security hole. Once I was SIM-swapped (when the attacker calls up a phone company and convinces them to redirect sms to their SIM). I had used it as a second factor at GoDaddy and had to act fast. GoDaddy had already allowed the attacker to authenticate with the sms (dumb!) and port the domain name. I realized what was happening only because the attacker sent “test” emails to my email at the domain. Had they not done that, I might have been none the wiser. I called GoDaddy and got them to cancel it, thankfully. Otherwise they’d have reset passwords armed with email AND phone number.

Since then I use the non-SMS SECOND FACTOR on most services, as NIST had been recommending for a decade now.

I personally recommend using a username+alias@gmail.com which gmail and others support, with a different but easy-to-remember alias per site, so social attackers can’t even correctly say your email to the dude on the phone.

Michael Terpin, a guy I know, got $27 million dollars in crypto stolen a decade ago by a SIM Swapper and sued AT&T for it. Not sure if he won… he moved to Puerto Rico to avoid taxes and brought Brock Pierce and other crypto bros with him LOL.